As a person who delivered pizza through high school, and college, it's just not that bad. And yes, driving 8 hours a night, stop and go, is bad for a car ... regardless if it is pizzas or people being delivered. (Pizza delivery is worse, I'd often deliver 8 pizzas an hour average on Friday nights, try that with people!)
However, I assure you I did not need to spend $500/week on repairs, 20 years ago. That metric has certainly not changed now. An example, by that metric, there are many brand new cars for under $15kUSD (pandemic issues are not part of this argument).
At $500/week income, and by your logic therefore $500 per week in "car repairs", one could buy a new car every 30 weeks, or about twice per year. And as a person who delivered pizza nightly, 8 hours, 5 days per week, you wouldn't even new tires in that 6 months, or brake pads, or ... well.. anything.
Personally, I used to buy used, but where high-cost items are in good shape. EG, transmission, etc, etc. I bought 2 cars in the 6 years I delivered pizza. Each 6+ years old, each only requiring tires, brake pads+rotors from time to time.
When it came time for a big repair? That's when I bolted to the second car.
My point in all of this, is that yes -- you pay for repairs. But the numbers I hear being thrown around, are just extremely excessive.
Taxi companies, for all of their faults, can order fleet vehicles that minimize maintenance costs. Its a lot easier to maintain 100x of the same car, with the same parts, with the same maintenance crews/training, rather than 100x individuals all spending full rate on their own car maintenance fees.
Whatever vehicle is most efficient (ie: Prius for the last decade), can serve as the low-maintenance backbone of your car network.